Broken Timing Belt AFN: Causes and Troubleshooting

Hello everyone,

A few weeks ago, the timing chain broke on a specific car. I thought, 'Okay, new timing chain and everything should be fine,' but I was wrong.

The old belt had been in use for 3 years and just under 35,000 km (total mileage: 302,678 km!), and it seems to have worn down on the pulley to the point where it became only half its original width before eventually breaking. The remaining portion was found as frayed fluff.

When I installed the new timing belt, I noticed that it was running on the outermost edge of the lower crankshaft pulley and also rubbing against the pulley. After some searching, I occasionally came across mentions of the ESP console in relation to this issue.
I took them out now too, but you really don't see anything.
I also considered the possibility of a faulty ESP (Electronic Stability Program) module, but I dismissed it after reinstalling it.
The intermediate shaft's bearing ring was also a topic, but I dismissed it again because I believe the problem originates further up the system, specifically from the ESP (Electronic Stability Program).

Now the question is, how do I get the belt back to where it needs to be?
How can you determine if the console is working properly?
This one is also not particularly cheap right now .

I'm already grateful for any advice you can offer. If you need more pictures, I will provide them later.

Classic problem! The pump urgently needs new bearings. These are worn out! Getting it fixed at a Bosch service center will be somewhat expensive. You can find a pump in similar condition on eBay. Therefore, I would choose to go to the Bosch service center. However, the cost-benefit ratio definitely needs to be considered.

The fairy tale about the spoiled console? No way! I've heard that story enough times! Best regards.

Hi Diesel_Rudi,
Could you please elaborate on what specific observations you made regarding the bearings of the ESP (Electrostatic Precipitator) shaft – specifically, radial clearance, axial clearance, or any signs of stiffness or difficulty in rotation?
hg
Herbert.

The game has a slight amount of play both axially and radially; however, when the pulley is removed, there is no noticeable play.
It's surprising that the bearings are failing, especially since the car itself only has about 100,000 km on it.
I had to install an AT pump back then because of issues with the quantity setting device and other related components.

Hi,
Without the pulley wheel, the lever is smaller, which is why less play can be felt. Ideally, there should be no radial play. If you feel any play, try measuring it.
Perhaps you might want to take a look at these topics:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.
See also the search function: Console, ESP Console.
I haven't experienced that problem with my car yet, even though it has almost 370,000 kilometers (or miles).
Perhaps you could also check the toothed wheels for play and for any signs of damage ("eggs").
Sure, here is the translation of the text from German to English:

"vg" translates to "very good" in English.
Herbert.

When checking for radial play, it's important to note that it is only truly noticeable and measurable in the direction of the shaft's load. The wear limit is approximately 3/10mm. I recently encountered a similar issue, likely caused by an overly tight belt. After replacing the ESP (Electronic Stability Program) bearing bushings, the belt runs straight again.

Hi,
How can a timing belt be overtightened? It seems that this can only happen if you ignore the specified adjustment parameters. The adjustment of the tensioning rollers is clearly defined.
Sure, here is the translation of the text from German to English:

"vg" translates to "very good" in English.
Herbert.

I'm sure the rhyme was correct; I specifically checked it again during the last change.
We have now realigned the mounting bracket and properly tightened the pump, which created about 2mm of clearance between the pulley on the crankshaft and the engine block. This should prevent it from rubbing anymore.
I will still keep an eye on the wear and tear of the width. If anything else happens there, the pump will be removed.

Thank you for your help.

That's almost more than trivial!!! Of course, the pump is subjected to radial stress. Especially during startup! The diagnosis is even simpler: Observe the inlet point, where the pump was new. You'll see a smooth surface there. It's impossible to miss! Everything else is ignorance! If the belt moves towards the longitudinal member, it's obvious. Usually, you'll have significant wear on the timing cover.

Best regards,